It really doesn't matter. The total amount of chlorine produced is going to be the same. If you lose 3ppm of FC in a 24 hour period then whenever you run the unit it's going to have to make 3ppm of FC in a 24 hour period whether you rung it during the day or at night.

My only thinking is since it is easier to produce chlorine when the water is at a cooler temp and the sun isn't burning it off, would it be harder on the equipment to have to up the percentage on the output to compensate for the sun and hotter water temps during the day? Just thinking out loud. It may have the same effect on the equipment.

My thinking is like Bama's. If you lose 3ppm a day you have to make 3ppm per day either way. I just like the idea of keeping it more constant By generating it as it's being used as opposed to letting it decline all day and replenishing it at night. I think that is one of the advantages of a SWG vs BBB. The other is not hauling and storing bleach or chlorine.